Rotary burner for vacuum tube manufacture



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w. MOSCRIP ROTARY BufiNE FOR VACUUM TUBE MANUFACTURE Filed May 9, .1944

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Patented Sept. 30, 1947 UNITED STATES PATENT OFFICE ROTARY BURNER FOR VACUUM TUBE MANUFACTURE Application May 9, 1944, Serial No. 534,791 In Great Britain May 21, 1943 10 Claims. (Cl. 158-99) The present invention relates to glass-working machinery, and in particular to machines for performing sealing operations and the like on vacuum tubes and similar devices.

It applies to the type of machine in which the part to be worked is held fixed, and sets of gas burning nozzles are rotated r oscillated co-axia1- 1y about the part so as to heat it uniformly. The rotary heads for this kind of operation present certain difliculties in design associated with the gas supply to the moving burners, since it is necessary to provide a rotary coupling which is free from leaks at the joints between the fixed and moving parts. The object of the present invention is to overcome these difliculties with a simple arrangement in which the effects of wear are automatically taken up so that the device does not become leaky after a period of use.

According to the invention, there is provided a rotary heating head for glass-working comprising two members adapted for relative rotation and enclosing one or more gas fuel chambers sealed by surfaces of the said members movable relativelyin contact, resilient means being provided for applying continuous pressure to the surfaces in contact for the purpose of maintaining the seals.

The invention will be described with reference to the accompanying drawing in which:

Fig. 1 shows a partly sectioned side view of a rotary head according to the invention; and

Fig. 2 shows a partly sectioned top View thereof.

The rotary head shown in Figs. 1 and 2 com prises a main rotating shaft I driven in any suitable way (not shown) and fixed thereto are two discs 2 and 3 spaced apart, the inner faces of. the discs being finished flat and true. In the space between the two discs is placed an annular member comprising two annular portions or annuli I and 5 which are urged apart by three or any suitable number of symmetrically spaced springs 6 located in drillings l and 8 in the portions 4 and 5, and imprisoned by grub screws 9. The outer peripheries of the annular portions 4 and 5 are connected by circular metallic bellows I!) soldered or otherwise hermetically sealed to each portion and lying in peripheral recesses cut to receive the pleatings of the bellows. The inner peripheries of the annular portions are similarly sealed by circular metallic bellows II of smaller diameter.

In this manner two separate chambers are formed, namely a central circular chamber bounded by the bellows I I, the inner peripheries of the portions 4 and 5, and the shaft I; and an outer annular chamber comprising the thin disclike space between the two portions bounded by the inner and outer bellows. V

The rotating disc 2 is provided on the outer surface with twelve gas burning nozzles arranged in a circle, six of which are designated I2, and communicate by means of individual ducts I3 (one of which is shown in each figure) with the inner chamber. The remaining six nozzles, designated I4, which may be placed alternately with the nozzles I2 as shown, communicate by means of individual ducts I5 with a circular groov I6 of semi-circular section cut on the inner face of the disc 2. This groove registers with a similar groove I'I cut in the outer surface of the annular portion 5 to form therewith a substantially complete circular channel which communicates with the outer chamber through a single duct I8.

Gas or fuel is supplied to the inner chamber through a single passage I9, for example by a 'tube 20 (Fig. 2) screwed therein and connected to a gas main. Similarly, gas is separately supplied to the outer chamber through a single passage ZI by the tube 22 shownin Fig, 2.

It will be understood that the assembly comprising the two annular portions 4 and 5 and the bellows I0 and II are held stationary by any means (not shown) while the two discs 2 and 3 rotate with the shaft I, so that the connections to the gas supply are fixed. The portions 4 and 5 are preferably constructed of bronze, and the discs 2 and 3 of cast iron, and the device should be carefully run in before it is used, until the surfaces have bedded to ether so that they are gastight. If the running-in be properly done, relatively light pressure by the springs 6 is sufiicient to seal the device. A lubricant such as graphite may be applied through the drillings 23 which are closed by thumbscrews 24, and it will be seen that all wear will be taken up by the springs, and the bedding of the surfaces will tend to improve with use.

As already mentioned, different fuel or fuel mixtures may be supplied to the two sets of burner nozzles in order to obtain different degrees of heating for different operations. Obviously, all the nozzles may be supplied with the same fuel if desired, or alternatively, for example, oxygen may be supplied to one chamber and a. fuel as to the other, and the necessary mixing may be done in the flames above the nozzles. Evidently the arrangement is very flexible and may be adapted to various modes of operation. It is to be noted that the method of sealing the chambers provides easy relief of the pressures generated if any ac- 3 cidental explosions should occur in the chambers.

The work t be heated will generally be held fixed by appropriate means (not shown) above the outer face of the disc 2 so that the flames from the nozzles mounted thereon may conveniently play upon it. If desired the usefulness of the rotating head may be increased by providing appropriate means to allow it to be moved axially while rotating so that the work may be progressively shaped.

It is to be noted that if desired either the inner or the outer bellows could be omitted if only one fuel chamber is required. In this case the design may be further simplified by omitting the grooves I6, I! and the ducts 15, I8 and 2!, the gas being supplied through the passage 19; and then all the nozzles would communicate with the central chamber by ducts such as 13.

It will be evident that the device may be variously modified within the scope of the invention. For example, the numbers of nozzles carried by the disc 2 can be varied as desired, and the details of the connections to the inner and outer chambers may be modified in numbers of ways.

The arrangement of the invention is clearly applicable without any modification to the case where it is desired to oscillate the burners about the work instead of to rotate them continuously.

It will be obvious also that the rotary head according to the invention can be used for working other fusible materials besides glass. The term glass-working is therefore to be understood to cover the working of any like fusible material.

What is claimed is:

1. A rotary heating head comprising a pair of spaced co-axial discs, a rotatable shaft co-axial with and attached to Said discs, at non-rotatable co-axial annular member located between said discs and having two opposite surfaces thereof in yieldable contact respectively with the inner surfaces of said discs, whereby there is formed at least one fuel chamber between said discs sealed at said surfaces, means for applying continuous sealing pressure to said surfaces in contact, and a plurality of gas burning nozzles on one of said discs, each nozzle communicating with said one chamber.

2. A rotary head according to claim 1 in which said member comprises two parallel annular portions spaced apart to form a gap and a co-axial circular bellows member which connects together and closes said gap to form at least part of the wall of a fuel chamber.

3. A rotary head according to claim 1, in which said member comprises two parallel annular portions spaced apart to form a gap and a co-axial circular bellows member which connects together and closes said gap to form the side Wall of one fuel chamber, and also including a plurality of springs positioned between said annular portions and acting to urge them apart and into contact with the corresponding discs, thereby applying continuous pressure to the sealing surfaces between said annular portions and said discs.

4. A rotary head according to claim 1, in which said annular member includes two spaced-apart portions and bellows annularly arranged inside said two portions and closing the gap therebetween so as to form one wall of a fuel chamber.

5. A rotary head according to claim 1, in which said annular member includes two spaced-apart portions and bellows annularly arranged outside said two portions and closing the gap therebetween so as to form one wall of a, fuel chamber.

6. A rotary head according to claim 1, in which said annular member includes two spaced-apart portions and two bellows annularly arranged, one inside and one outside said two portions and closing the gap therebetween so as to form two walls of a fuel chamber between said portions.

'7. A rotary head according to claim 1, in which said annular member includes two spaced-apart portions and bellows annularly arranged inside said two portions and closing the gap therebetween so as to form one wall of a fuel chamber, one of said annular portions being provided with a passage communicating with the space between said annular portions for supplying fuel to said space.

8. A rotary head according to claim 1, in which said annular member includes two spaced-apart portions and bellows annularly arranged inside said two portions and closing the gap therebetween so as to form one wall of a fuel chamber, in which a co-axial circular channel has been formed in the surfaces between the disc carrying the gaseous fuel outlets and the corresponding annular portion by cutting equal co-axial grooves in each of said surfaces, and in which said circular channel communicates with predetermined fuel nozzles, and also with the space between said annular portions.

9. A rotary head according to claim 1, in which said discs are constructed of cast iron and said annular member of bronze.

10. A rotary gas-tight fixture comprising a rotatable shaft, two spaced parallel discs coaxial with and mounted on said shaft, two non-rotatable annuli between said discs radially spaced from said shaft and spring pressed against the inner surfaces of said discs, the contacting surfaces of said discs and annuli being smooth and gas tight, a bellows coaxial with and hermetically sealed at its ends to said annuli, said discs, annuli, shaft and bellows forming a. chamber, one of said discs having fluid ducts communicating with said chamber, and one of said annuli having a passage for supplying fuel for said chamber.

WILLIAM ROSWELL MOSCRIP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,212,842 McGovan Aug, 27, 1940 2,121,627 Donavan et al June 21, 1938 2,349,822 Gardner May 30, 1944 2,287,945 Purat June 30, 1942 

